The present invention relates to automatic washers, and more particularly to an improved fluid recirculation system for an automatic washer.
Vertical axis automatic washers generally include fluid handling systems for filling a washer tub with a wash fluid (generally a water and detergent solution) and then after an agitation portion of the cycle, draining the wash fluid from the tub. A subsequent rinse with fresh water and draining of the rinse water are also provided. During the agitate portion of the wash cycle, oftentimes the agitator provides a pumping action causing the wash fluid to be recirculated through the wash tub, sometimes through filter elements, such as disclosed in U.S. Pat. Nos. 4,338,802; 4,357,813; 4,402,198; 4,417,457; 4,419,870; 4,420,951 and 4,420,952, all assigned to the assignee of the present application. The recirculation of wash liquid by the above listed patents generally occurs during the agitate portion of the wash cycle and involves recirculating the wash liquid within the wash tub, and oftentimes through or along a portion of the agitator body.
U.S. Pat. No. 4,784,666, assigned to the assignee of the present application, discloses a high performance washing process for vertical axis automatic washers which includes the recirculation of wash fluid prior to the agitate portion of the wash cycle. That patent describes, as a particular embodiment of the invention, to load a charge of detergent into the washer along with a predetermined amount of water, preferably prior to admitting a clothes load into the basket to assure that the concentrated detergent solution will initially be held in a sump area of the wash tub so that the detergent will be completely dissolved or mixed into a uniform solution before being applied to the clothes load. It is also suggested that the addition of an anti foaming agent may be desireable. No particular arrangement is provided for mixing the detergent and water to provide a uniform solution, nor is any particular means described for assuring that the amount of wash liquid within the tub during the spin wash portion of the wash cycle is an amount which is slightly in excess of the saturation level for the clothes load.
U.S. Pat. No. 4,503,575, assigned to the assignee of the present application, discloses the use of an additive mixing tank and a recirculation system for directing wash liquid into the mixing tank at selected portions of the wash cycle and for admitting selected additives to the wash liquid within the mixing tank prior to dispensing such additives into the wash tub.